In your paragraphs about junk collecting you fail to mention that you can highlight junk you want. Initially I found myself picking up EVERYTHING and having to drop that one last thing to get myself to 199.9 so I could fast-travel away, stash my junk, and fast-travel back to pick up where I left off. Later I learned to load up my companion (tip: when it says your companion can't hold anymore, try sorting your junk by weight and then give him/her the ones with the lowest weight - it's possible the companion can handle some more but not as much as first thing you tried) but we would still max out collectively and have to go and dump our stash. Power Suits allow you to carry more, but it was never enough. But there is a solution.
It took me a while to understand tagging, and it really helped me cut back on the urge to pick up EVERYTHING because something might be critical. When you're trying to build or mod or cook something and you don't have the right ingredients you can click the option to Tag the missing components. Imagine you're trying to mod your Power Suit and it says you're missing ceramics. Tag it for search, and the next time you're wandering around and look at a Coffee Mug you will see a magnifying glass symbol next to it, indicating that it contains the component you're looking for. You can also look at your Junk list in Pip Boy and click to look at it in Components view. Instead of seeing that you have 3 Coffee Mugs you will see that you have 3 ceramics, or whatever. You can do the same in your Workbench, and tag components there too, I believe. Now I can resist the urge to pick up EVERYTHING, yet I know I won't miss out on what I need. There is even a Perk you can select that highlights anything you're looking for with a green glow so you can spot it from a distance instead of having to hover over it to see. I had been ignoring plungers but now they glow to remind me that they're a good source of the rubber component that I've been looking for.
Also, keep in mind that this is all unnecessary if you're not into building or modding. You could, really, play the whole game with a minimum of building or modding. When it is required to build something in order to complete a mission, the components you need are always there in the immediate environment. You may just need to junk a car or bunch of trees to get the necessary steel or wood. Now that I've gotten a better feel for the inventory management I only pick up stuff I've highlighted, named stuff (like "Sebastian's Pocket Watch"), perks like comic books or bobble-heads which give you something, ammo (which always has a weight of 0), and weapons/armour marked with an asterix * which indicates they've got a special feature.
